2,721 research outputs found
Self-Healing Computation
In the problem of reliable multiparty computation (RC), there are
parties, each with an individual input, and the parties want to jointly compute
a function over inputs. The problem is complicated by the fact that an
omniscient adversary controls a hidden fraction of the parties.
We describe a self-healing algorithm for this problem. In particular, for a
fixed function , with parties and gates, we describe how to perform
RC repeatedly as the inputs to change. Our algorithm maintains the
following properties, even when an adversary controls up to parties, for any constant . First, our
algorithm performs each reliable computation with the following amortized
resource costs: messages, computational
operations, and latency, where is the depth of the circuit
that computes . Second, the expected total number of corruptions is , after which the adversarially controlled parties are
effectively quarantined so that they cause no more corruptions.Comment: 17 pages and 1 figure. It is submitted to SSS'1
Distributed Failure Restoration for Asynchronous Transfer Mode (ATM) Tactical Communication Networks
Asynchronous Transfer Mode (A TM) is an attractive choice for future military
communication systems because it can provide high throughput and support multi-service
applications. Furthermore its use is consistent with the 'off the shelf technology
policy that is currently operated by the Defence Engineering Research Agency of Great
Britain. However, A TM has been developed as a civil standard and is designed to
operate in network infrastructures with very low failure rates. In contrast, tactical
networks are much less reliable. Indeed tactical networks operate on the premise that
failures, particularly node failures, are expected. Hence, efficient, automatic failure
restoration schemes are essential if an A TM based tactical network is to remain
operational. The main objective of this research is the proposal and verification of one
or more new restoration algorithms that meet the specific requirements of tactical
networks.
The aspects of ATM networks that influence restoration algorithms' implementation are
discussed. In particular, the features of A TM networks such as the concept of Virtual
Paths Virtual Channels and OAM (Operation And Maintenance) mechanisms that
facilitate implementation of efficient restoration techniques. The unique characteristics
of tactical networks and their impact on restoration are also presented.
A significant part of the research was the study and evaluation of existing approaches to
failure restoration in civil networks. A critical analysis of the suitability of these
approaches to the tactical environment shows no one restoration algorithm fully meets
the requirements of tactical networks. Consequently, two restoration algorithms for
tactical A TM networks, DRA-TN (Dynamic Restoration Algorithm for Tactical
Networks) and PPR-TN (Pre-planned Restoration Algorithm for Tactical Networks), are
proposed and described in detail. Since the primary concern of restoration in tactical
networks is the recovery of high priority connections the proposed algorithms attempt to
restore high-priority connections by disrupting low-priority calls. Also, a number of
additional mechanisms are proposed to reduce the use of bandwidth, which is a scarce
resource in tactical networks.
It is next argued that software simulation is the most appropriate method to prove the
consistency of the proposed algorithms, assess their performance and test them on
different network topologies as well as traffic and failure conditions.
For this reason a simulation software package was designed and built specifically to
model the proposed restoration algorithms. The design of the package is presented in
detail and the most important implementation issues are discussed. The proposed
restoration algorithms are modelled on three network topologies under various traffic
loads, and their performance compared against the performance of known algorithms
proposed for civil networks. It is shown that DRA-TN and PPR-TN provide better
restoration of higher priority traffic. Furthermore, as the traffic load increases the
relative performance of the DRA-TN and PPR-TN algorithms increases. The DRA-TN
and PPR-TN algorithms are also compared and their advantages and disadvantages
noted.
Also, recommendations are given about the applicability of the proposed algorithms,
and some practical implementation issues are discussed. The number of problems that
need further study are briefly described.Defence Engineering Research Agency of Great Britai
Internet of Things-aided Smart Grid: Technologies, Architectures, Applications, Prototypes, and Future Research Directions
Traditional power grids are being transformed into Smart Grids (SGs) to
address the issues in existing power system due to uni-directional information
flow, energy wastage, growing energy demand, reliability and security. SGs
offer bi-directional energy flow between service providers and consumers,
involving power generation, transmission, distribution and utilization systems.
SGs employ various devices for the monitoring, analysis and control of the
grid, deployed at power plants, distribution centers and in consumers' premises
in a very large number. Hence, an SG requires connectivity, automation and the
tracking of such devices. This is achieved with the help of Internet of Things
(IoT). IoT helps SG systems to support various network functions throughout the
generation, transmission, distribution and consumption of energy by
incorporating IoT devices (such as sensors, actuators and smart meters), as
well as by providing the connectivity, automation and tracking for such
devices. In this paper, we provide a comprehensive survey on IoT-aided SG
systems, which includes the existing architectures, applications and prototypes
of IoT-aided SG systems. This survey also highlights the open issues,
challenges and future research directions for IoT-aided SG systems
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Traffic engineering multi-layer optimization for wireless mesh network transmission a campus network routing protocol transmission performance inhancement
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel UniversityThe wireless mesh network is a potential network for the future due to its excellent inherent characteristic for dynamic self-healing, self-configuration and self-organization. It also has the advantage of easy interoperability networking and the ability to form multi-linked ad-hoc networks. It has a decentralized topology, is cheap and highly scalable. Furthermore, its ease in deployment and easy maintenance are other inherent networking qualities. These aforementioned qualities of the wireless mesh network bring advantages to transmission capability of heterogeneous networks. However, transmissions in wireless mesh network create comparative performance based challenges such as congestion, load-balancing, scalability over increasing networks and coverage capacity. Consequently, these challenges and problems in the routing and switching of packets in the wireless mesh network routing protocols led to a proposal on the resolution of these failures with a combination algorithm and a management based security for the network and its transmitted packets. There are equally contentious services like reliability of the network and quality of service for real-time multimedia traffic flows with other challenges such as path computation and selection in the wireless mesh network.
This thesis is therefore a cumulative proposal to the resolution of the outlined challenges and open research areas posed by using wireless mesh network routing protocol. It advances the resolution of these challenges in the mesh environment using a hybrid optimization – traffic engineering, to increase the effectiveness and the reliability of the network. It also proffers a cumulative resolution of the diverse contributions on wireless mesh network routing protocol and transmission. Adaptation and optimization are carried out on the wireless mesh network designed network using traffic engineering mechanism and technique. The research examines the patterns of mesh packet transmission and evaluates the challenges and failures in the mesh network packet transmission. It develops a solution based algorithm for resolutions and proposes the traffic engineering based solution.. These resultant performances and analysis are usually tested and compared over wireless mesh IEEE802.11n or other older proposed documented solution.
This thesis used a carefully designed campus mesh network to show a comparative evaluation of an optimal performance of the mesh nodes and routers over a normal IEE802.11n based wireless domain network to show differentiation by optimization using the created algorithms. Furthermore, the indexes of performance being the metric are used to measure the utility and the reliability, including capacity and throughput at the destination during traffic engineered transmission. In addition, the security of these transmitted data and packets are optimized under a traffic engineered technique. Finally, this thesis offers an understanding to the security contribution using traffic engineering resolution to create a management algorithm for processing and computation of the wireless mesh networks security needs. The results of this thesis confirmed, completed and extended the existing predictions with real measurement
MICRORNA FUNCTIONS IN UV-INDUCED CUTANEOUS SQUAMOUS CELL CARCINOMA
Cutaneous squamous cell carcinoma (cuSCC) is the second most common skin cancer, for which long term UV exposure and chronic wounding are the dominant risk factors. Despite these clinically established connections, little is understood about the early molecular response of human skin to UV exposure and its connection to acute wounding and cuSCC. Thus, our goal is to find common and specific signatures driven by UV-exposure and wounding as a means of developing new approaches for treating and preventing cuSCC.
Here, we perform integrated analyses of RNA-seq and miR-seq on 3 datasets: (1) UV-unexposed and acute UV-exposed human skin, (2) public dataset on acute wound healing and (3) our previously published dataset on normal skin and cuSCC from humans. We find that biological signatures and processes regulated by acute UV exposure and wounding has profound similarity.
Through RNA-seq and miR-seq on matched normal skin and cuSCC tumors from humans and a UV-driven mouse model, as well as acute UV-exposed human skin, we were able to identify a group of miRs that change both in cuSCC development and following UV exposure. We previously reported that miR-21-5p and miR-31-5p overexpression correlates with the development of UV-induced cuSCC in human. This is also true for our analysis where we find that these miRs as well as miR-21-3p are upregulated by more than 6-fold in cuSCC (compared to normal skin) and more than 2.5-fold in UV-exposed skin (compared to unexposed skin). In addition, we identify that miR-340-5p and let-7i-5p are novel candidates that have not been previously linked to either cuSCC development or the UV response of human skin.
This suggests that these changes in miRNA-RNA are important early events that regulated by both UV-exposure and wounding which eventually can promote cuSCC initiation. Thus, our findings suggest that UV-exposed skin, wound and cuSCC share various common signatures, which can be potentially validated as chemopreventive targets for cuSCC
Implementation of AES using biometric
Mobile Adhoc network is the most advanced emerging technology in the field of wireless communication. MANETs mainly have the capacity of self-forming, self-healing, enabling peer to peer communication between the nodes, without relying on any centralized network architecture. MANETs are made applicable mainly to military applications, rescue operations and home networking. Practically, MANET could be attacked by several ways using multiple methods. Research on MANET emphasizes on data security issues, as the Adhoc network does not befit security mechanism associated with static networks. This paper focuses mainly on data security techniques incorporated in MANET. Also this paper proposes an implementation of Advanced Encryption Standard using biometric key for MANETs. AES implementation includes, the design of most robust Substitution-Box implementation which defines a nonlinear behavior and mitigates malicious attacks, with an extended security definition. The key for AES is generated using most reliable, robust and precise biometric processing. In this paper, the input message is encrypted by AES powered by secured nonlinear S-box using finger print biometric feature and is decrypted using the reverse process
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